Gun barrel

ABSTRACT

1. IN A GUN BARREL OF THE TYPE HAVING A CHAMBER FOR RECEIVING A PROJECTILE HAVING A BODY PORTION AND AN ENLARGED SOMEWHAT CONICAL BASE, LANDS AND GROOVES IN THE GUN BARREL EXTENDING FROM SAID CHAMBER FOR RECEIVING SAID ENLARGED BASE TO THE MUZZLE OF SAID GUN BARREL, AND THE GROOVES BEING TAPERED IN WIDTH FROM A MAXIMUM WIDTH AT SAID CHAMBER FOR SAID CONICAL BASE TO A MINIMUM WIDTH ADJACENT SAID MUZZLE WHEREBY SAID ENLARGED BASE OF A PROJECTILE MAY BE FORMED INTO UPSTANDING FINS AS SAID PROJECTILE IS MOVED THROUGH SAID GUM BARREL TOWARD THE NUZZLE, THE COMBINATION THEREWITH OF THE IMPROVEMENT TO REDUCE BALLOTING OR WOBBLE OF THE PROJECTILE IN   THE GUN BARREL AND ENHANCE ACCURACY IN ITS FLIGHT AFTER LEAVING THE GUN BARREL, SAID IMPROVEMENT INCLUDING THE SAID BODY PORTION BEING CYLINDRICAL IN FRONT OF SAID FINS AND SAID LANDS EXTENDING INWARDLY TRANSVERSELY OF THE GUN TO CONTACT AND GUIDE THE CYLINDRICAL BODY PORTION OF A PROJECTILE DURING SUBSTANTIALLY ITS ENTIRE MOVEMENT WITHIN THE GUN BARREL.

March 1971 C.WALTON MUSSER 3,566,528

Filed April 23, 1958 2 Sheets-Sheet 1 lNVEN C WALTON M ER BY WEAZAJ IIM.2 .W 7- fl-RW y March 2, 1971 C.WALTON MUSSER 3,566,528

GUN BARREL 2 Sheets-Sheet 2 Filed April 23, 1958 INVENTOR. C WALTONMUSSEIR v I BY W6- ,a/wa

United States Patent Ofice 3,566,528 GUN BARREL C Walton Musser,Beverly, Mass., assignor to the United States of America as representedby the Secretary of the Army Filed Apr. 23, 1958, Ser. No. 731,078 Int.Cl. F41c 21/00; F42b 11/00, 15/00 US. C]. 42-78 3 Claims The inventiondescribed herein may be manufactured and used by or for the Governmentfor governmental purposes Without the payment of an royalty thereon.

This invention relates to a gun barrel for small arms ammunition weaponsystems and to a method of permanently reshaping a projectile into afiechette, or small steel dart with fins or vanes, during its passagethrough the gun barrel. Heretofore, the only way flechettes wereaccurately formed was by a molding process that was not only costly, butrequired a costly means to affix them to cartridge cases for launching.

The purpose of this invention is to provide a gun barrel which iscapable of permanently reshaping a specially formed bullet into aflechette during the bullets passage through the bore of the gun, thebore diameter being constant from the breech to the muzzle to eliminateballoting or wobble of the projectile therein, as a result of which thebullet will have superior exterior ballistics.

The large area of the base of the bullet presented to the powder gasesprior to its reshaping in the barrel imparts a greater force to thebullet improving its interior ballistics while the reshaped bullet onleaving the muzzle of the gun barrel offers less external resistancefurther improving its external ballistics.

More specifically, the invention consists in providing the gun barrelwith tapered lands and grooves that extend from the breech to the muzzleto act as forming dies to reshape a part of the bullet and, if desired,curve the fins to impart rotation to the projectile as it leaves themuzzle. Lands in the prior art are tapered for a relatively shortdistance from the breech in order to facilitate introduction of aprojectile wtih a pre-engraved surface on its outer periphery.

A method of reshaping a projectile while within the weapon has beenemployed by Moore (Pat. No. 2,089,- 219) wherein the lands squeezed downthe preformed tail of a missile or bullet. However, this has not beenfound to be satisfactory.

In a gun of this type the accuracy of the projectile is at the mercy ofthe uniformity of squeeze-down on the projectile. For example, if theprojectile were to differentially deform so that one side of it deformedearlier than the other side, the projectile would be givn a sidecomponent velocity and as a consequence it would either be improperlyformed or it would start balloting or wobbling Within the gun bore,since the front cylindrical part of the projectile is unsupported. Ineither case, its accuracy upon leaving the muzzle of the gun isdestroyed. Very frequently these projectiles were so malformed that theexternal ballistics were seriously impaired.

In contrast to these, the proposed invention preferred to maintain thegroove and bore diameter constant from breech to muzzle. By so doing thecylindrical portion of the projectile, which preceded the deformableportion, coul fit within the bore diameter and be positively guidedthroughout its entire journey in the barrel.

To these and other ends, the invention consists in the construction,arrangement and combination of elements described hereinafter andpointed out in the claims formig a part of this specification.

A practical embodiment of the invention is illustrated in theaccompanying drawings wherein the characters of ref- 3,566,528 PatentedMar. 2, 1971 erence indicate corresponding parts throughout the severalviews and wherein:

FIG. 1 is a longitudinal sectional view of a gun barrel constructed inaccordance with the invention.

FIGS. 2, 3 and 4 are sectional views on the respective lines of FIG. 1.

FIG. 5 is a developed view taken at the outside diameter of the grooveson lines 5--5 of FIG. 1.

FIG. 6 is a longitudinal sectional view of a bullet of the preferredembodiment before passing through the gun barrel.

FIG. 7 is a rear end view of FIG. 6.

FIG. 8 is a view in side elevation of the bullet after passing throughthe gun barrel.

FIG. 9 is a rear end view of FIG. 8.

FIG. 10 is a longitudinal sectional view of an alternative embodiment ofbullet before passing through the gun barrel.

FIG. 11 is a rear end view of FIG. 10.

FIG. 12 is a view in side elevation of the bullet shown in FIG. 10 afterpassing through the gun barrel.

FIG. 13 is a rear end view of FIG. 12.

FIG. 14 is a longitudinal sectional view of another alternativeembodiment of the bullet before passing through the gun barrel.

FIG. 15 is a rear end view of FIG. 14.

FIG. 16 is a view in side elevation of the bullet shown in FIG. 14 afterpassing through the gun barrel.

FIG. 17 is a rear end view of FIG. 16-.

Referring to FIGS. 1 to 4, the gun barrel 20 has a bore 23 in which thelands 21 are gradually widened from a point at the projectile receivingchamber to the muzzle, the bore diameter 23 being uniform throughout theentire length of the gun barrel with the result that the grooves 22 aregradually narrowed in width toward the muzzle but are at a uniform depthor diameter 24 (which approximately corresponds to the diameter of theprojectile receiving chamber in which is the enlarged base 29 of theprojectile body 28) from the projectile receiving chamber to the muzzle.The lands 21 and grooves 22 may also be cut with a helical angle inorder to impart spin to the projectile on leaving the muzzle. The landsmay be tapered in width from the portion of the projectile receivingchamber in which the enlarged base 29 is located, to adjacent the muzzleso that the width of the grooves corresponds to the desired finthickness.

A preferred form of bullet for use with the gun barrel is shown in FIGS.6 to 9 and consists of a body 28, preferably of steel, and an integralenlarged cylindrical base or tail 29 made of lead or other readilydeformable material, and capable of being permanently reshaped, the saidtail being approximately one-quarter as long as the body. The diameterof the base 29 is approximately three times the diameter of the body andequal to the maximum diameter 24 of the grooves 22.

The gun barrel 20 with its lands 21 and grooves 22 constitutes a formingdie which acts on the base 29 of the bullet to permanently reshape itforming the fins 30 as shown in FIGS. 8 and 9. During travel of thebullet through the gun barrel 20, its body 28 is in constant contactwith the gun barrel 23 whereby the bullet is given stability while itsbase 29 is being reshaped.

An alternative embodiment of bullet for use with the gun barrel is shownin FIGS. 10 and 11 and consists of a. body 31, preferably of steel andan integral enlarged hollow and readily deformable base 32, constitutinga conical-shaped tail approximately one-quarter as long as the body. Thediameter of the rear end of base 32 is the same as the maximum diameterof the grooves 24. The said base is formed with a conical-shaped cavitythrough which extends the body 31 of the projectile to the end of thebase. In this cavity and extending radially outward from the outsidediameter of the body of the projectile are four fins 33 spaced 90 apart,said fins meeting and merging into the Walls of the conical tail, thelatter being relatively thin so that it is readily deformable. The landsin the gun barrel, functioning as a forming die, act on the conical baseshearing the cone midway between the fins in the conical cavity, inaddition to bending said sheared portions against the fins duringpassage of the projectile through the gun barrel, so that theprojectile. emerges from the muzzle in the form of a fiechette as shownin FIGS. 12 and 13.

Another alternative embodiment of bullet for use with the gun barrel isshown in FIGS. 14 and 15, and consists of a body 34, preferably of steeland an integral enlarged readily deformable base 35 and 36 approximatelyonefourth as long as the body, said base comprised'of a series of finsextending radiall outward from the body to a diameter essentially equalto the maximum diameter of the grooves 24, said fins being formed into aseries of interconnected V shaped members as the fins encircle the bodyof the bullet. The lands in the gun barrel, functioning as a formingdie, act on the V shaped members opening up the apices of the Vs at thetail end of the base and bending side 36 thereofagainst side 35 duringpassage of the projectile through the gun barrel, so that the projectileon emerging from the muzzle, is in the form of a flechette as shown inFIGS. 16 and 17..

I claim:

1. In a gun barrel of the type having a chamber for receiving aprojectile having a body portion and an enlarged somewhat conical base,lands and grooves in the gun barrel extending from said chamber forreceiving said enlarged base to the muzzle of said gun barrel, and thegrooves being tapered in width from a maximum width at said chamber forsaid conical base to a minimum width adjacent said muzzle whereby saidenlarged base of a projectile may be formed into upstanding fins as saidprojectile is moved through said gun barrel toward the muzzle, thecombination therewith of the improvement to reduce balloting or wobbleof the projectile in the gun barrel and enhance accuracy in its flightafter leaving the gun barrel, said improvement including the said bodyportion being cylindrical in front of said fins and said lands extendinginwardly transversely of the gun to contact and guide the cylindricalbody portion of a projectile during substantially its entire movementwithin the gun barrel.

2. A gun barrel according to claim 1 in which the fins formed from theenlarged base of the projectile have each a height about equal to thediameter of the cylindrical body portion of a projectile and the maximumdiameter of the fins is about 3 times that of the cylindrical bodyportion of the projectile.

3. A gun barrel according to claim 1 in which the lands and grooves areat an angle to the longitudinal axis of the gun barrel to impart atleast some rotation to the projectile on its longitudinal axis.

References Cited UNITED STATES PATENTS 50,433 10/1865 Trauth 42781,275,028 8/1918 Holter 42-78 2,089,219 8/1937 Moore 4278 EAMUEL W.ENGLE, Primary Examiner C. T. JORDAN, Assistant Examiner U.S. Cl. X.R.

